Spent Fuel Dry Storage: Challenges and Lessons

Learned From Recent Project Experience at Shutdown Nuclear

Plants in the U.S.

Kent S. Cole

President & CEO

NAC International

6/17/2015

Outline

1. Decommissioning status and trends

2. Decommissioning dry storage status & drivers

3. Decommissioning dry storage challenges

4. Recent decommissioning dry storage projects

5. Summary and Conclusion

2

U.S Decommissioning Market Status

3

Current nuclear plant status

• 99 Commercial reactors in operation (Compared to 104 in 2014)

• 5 Commercial reactors under construction (Vogtle [2 units], VC Summer [2 units], Watts Bar Unit 2)

Recent Shutdown Reactor Status:

.

All five recently shutdown reactors plan to proceed with prompt defueling into dry storage followed by a period of safe preservation prior to dismantlement and decontamination (D&D).

Plant Rating Shutdown Date Owner Reason

Crystal River 860 MWe February 2013 Duke Economics/Repairs

Kewaunee 566 MWe May 2013 Dominion Economics/Market

San Onofre 2&3 2,160 MWe June 2013 SCE Economics/Repairs

Vermont Yankee 635 MWe December 2014 Entergy Economics

U.S. Decommissioning Alternatives

4

SAFSTOR (deferred dismantlement) – Facility is placed and

maintained in a condition that allows the facility to be safely stored

until subsequent decontamination and dismantling (up to 60 years)

DECON – Facility is considered undergoing decontaminating and

dismantling to levels that permit release for unrestricted use

ENTOMB - Radioactive structures are encased onsite with grout or

concrete (provides structural protection and shielding). The facility

is then maintained and monitored until the radioactivity decays to a

level permitting restricted release of the property.

FACT: Of the 20 shutdown reactors with fuel onsite in the U.S., 9 are in

SAFSTOR, 4 are in DECON, and 7 have completed DECON

U.S Decommissioning Dry Storage

Status

5

Reactor Name Type MWth State License Issued

Shutdown Date

Status

Big Rock Point BWR 240 MI 5/1/1964 8/29/1997

DECON completed ISFSI on

site

Fort St. Vrain HTG 842 CO 12/21/1973 8/18/1989

Haddam Neck PWR 1,825 CT 12/27/1974 12/5/1996

Maine Yankee PWR 2,700 ME 6/29/1973 12/6/1996

Trojan PWR 3,411 OR 11/21/1975 11/9/1992

Rancho Seco PWR 2,772 CA 8/16/1974 6/7/1989

Yankee Rowe PWR 600 MA 12/24/1963 10/1/1991

Humboldt Bay 3 BWR 200 CA 8/28/1962 7/2/1976 DECON in progress ISFSI on

site

San Onofre 1(a) PWR 1,347 CA 3/27/1967 11/30/1992

Zion 1 PWR 3,250 IL 10/19/1973 2/21/1997

Zion 2 PWR 3,250 IL 11/14/1973 9/19/1996

LaCrosse BWR 165 WI 7/3/1967 4/30/1987 SAFSTOR with ISFSI on site

Crystal River 3 PWR 2,609 FL 12/3/1976 2/20/2013

SAFSTOR - ISFSI pending

Kewaunee PWR 1,772 WI 12/21/1973 5/7/2013

San Onofre 2 PWR 3,438 CA 2/16/1982 6/7/2013

San Onofre 3 PWR 3,438 CA 11/15/1982 6/7/2013

Vermont Yankee BWR 1,912 VT 3/21/1972 12/29/2014

Dresden 1 BWR 700 IL 9/28/1959 10/31/1978 SAFSTOR (other operating

reactors) Indian Point 1 PWR 615 NY 3/26/1962 10/31/1974

Millstone 1 BWR 2,011 CT 10/31/1986 7/21/1998

U.S Decommissioning Dry Storage

Status

6

There are fourteen (14) shutdown sites (sites with no

other operating reactors)

Ten (10) sites have relocated all spent fuel

into dry storage

Seven (7) completed DECON

Two (2) with DECON in process

One (1) in SAFSTOR

Four (4) sites (recent shutdowns) planning

to defuel within 5 years.

Note: Five (5) out of the ten (10) shutdown sites that have relocated

all spent fuel into dry storage systems use NAC cask technology

U.S. Decommissioning Recent Trends

7

SAFSTOR with prompt transfer of SF into dry storage

• Safety and robustness of dry storage (National Academy of Science study)

• Heightened stakeholder interest in getting pool out of shutdown pools post 9/11 and post-Fukushima

• Strong economic driver for removing fuel from pool

• $10M-$30M annually in reduced operations and security

staff

FACT: SAFSTOR with dry storage is viewed as having safety, security

and economical advantages over SAFSTOR with wet storage

U.S. Decommissioning Recent Trends

8

Dismantle & decommission when safe and economically viable

• Adequate decommissioning funds for project, including

risks

• Decommissioning fund growth (time value of money vs.

cost)

• Adequate time for decay of radioactivity for worker safety

and lower decommissioning costs

Some communities/stakeholders pushing for prompt decommissioning

Most stakeholders agree on accelerated movement of the fuel to dry storage regardless of the decommissioning approach.

U.S Decommissioning Dry Storage

Drivers

9

Safety – regulatory certification is a prerequisite

Security (physical) – including some assurance of capability

beyond design basis

Schedule - prompt loading and completion of ALL fuel loading – even damaged fuel, reconstituted assemblies,

lead test assemblies, high burnup fuel, “underburned”

fuel, etc.

Reasonable assurance of transportability

Low financial risk (for plant owner)

Decommissioning Dry Storage:

Zion Achievements/Lessons Learned

11

Designed and licensed revisions to address site

specific contents and operational requirements

• Damaged fuel was canned

• HBU fuel was canned (transport licensing

expediency in consideration of specific

contract requirements)

• Underburned (1 cycle) fuel reactivity

mitigated by loading with full length Rod

Control Cluster Assemblies

• Optimized loading plan for adhering to

offsite boundary dose rate limits with new

tighter site boundary (550 ft from ISFSI)

Used three different fabricators (Hitachi Zosen,

GEH, Peterson) to managed risk of delivery

Largest U.S. single dry storage campaign of 61

spent fuel casks in less than 55 weeks

13 June 17, 2015

Development of a 4-Zone cask loading pattern that permits the MAGNASTOR system to accept Kewaunee assemblies up to 1.8 kW from the last cycle (3- year cool time) with colder fuel (up to 0.8 kW) on the periphery to limit radiological dose

Design and deployment of and integrated yoke/chain hoist system to address seismic requirements and optimize canister transfer operations

Design and construction of an ISFSI facility that will accommodate MAGNASTOR casks to co-exist with horizontal systems already onsite

Develop a cask loading sequences that address site boundary dose rate requirements upon complete defueling of the Kewaunee spent fuel pool

Kewaunee Dry Storage Project: Site Specific

Requirements and Achievements

14 June 17, 2015

MAGNASTOR CoC Amendment 5 published in the U.S. Federal Register

TSCs and VCC liners in fabrication; progress on track

ISFSI expansion design and site A/E essentially complete

Kewaunee county permits approved

VCC construction campaign started in May

Operating procedures under development

Dominion Kewaunee Power Station

Project Status

Summary and Conclusion

15

• U.S. Decommissioning Trend on the Rise – 5 reactors shutdown since 2013

• A few other reactors are at risk of shutdown due to economic reasons (low power

costs in deregulated markets)

• Safety, Security and Economics drive a sound decommissioning strategy

• In fact, all of the shut down sites (those with no operating reactors) have

implemented or are planning to promptly implement dry storage

• The inherent safety of dry cask storage and the potential for a smaller plant security

footprint and associated benefits is a key driver for prompt defueling of shutdown

reactors.

• Two recent NAC projects demonstrate that dry storage technology selection

plays a key role in the safety and economics of a decommissioning defueling

operation.

• The Zion spent fuel transfer was the largest dry storage campaign ever implemented

in the U.S. and it was completed in about a year.

• Lessons learned and further innovations are being leveraged at the Kewaunee

project to achieve plant defueling a just 3.5 years after plant shutdown. This is about

two years earlier than originally planned

To meet U.S. regulations, a Damage Fuel Can (DFC) must confine gross

fuel particles, debris, or damaged assemblies to a known volume within

the cask, demonstrate that compliance with the criticality, shielding,

thermal, and structural requirements are met; and permit normal

handling and retrieval from the cask.

16

Decommissioning Dry Cask Storage:

Addressing Damaged Spent Fuel Contents